Debt instrument coupon rate.

No definition available.

Name:	geo_DebtInstrumentCouponRate
Namespace Prefix:	geo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Debt Default, Description of Violation or Event of Default, Failure to Comply with Other Indenture Agreements

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentDebtDefaultDescriptionofViolationorEventofDefaultFailuretoComplywithOtherIndentureAgreementsTerm
Namespace Prefix:	geo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Debt Default, Description of Violation or Event of Default, Interest Payment Failure, Term

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentDebtDefaultDescriptionofViolationorEventofDefaultInterestPaymentFailureTerm
Namespace Prefix:	geo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Debt Default, Description of Violation or Event of Default, Maximum Excess Proceeds on Sale of Asset

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentDebtDefaultDescriptionofViolationorEventofDefaultMaximumExcessProceedsonSaleofAsset
Namespace Prefix:	geo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Debt Instrument, Notice Period Prior to Redemption

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentNoticePeriodPriorToRedemption
Namespace Prefix:	geo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt Instrument, Redemption Period, Change in Control, Percentage of Principal Amount Redeemable

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentRedemptionPeriodChangeinControlPercentageofPrincipalAmountRedeemable
Namespace Prefix:	geo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt instrument yield to maturity percentage.

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentYieldToMaturityPercentage
Namespace Prefix:	geo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Date the debt agreement requires the first payment to be made, in CCYY-MM-DD format.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentDateOfFirstRequiredPayment1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

+ Details

Name:	us-gaap_DebtInstrumentFrequencyOfPeriodicPayment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(3))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

+ Details

Name:	us-gaap_DebtInstrumentPaymentTerms
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_FivePointEightSevenFivePercentSeniorNotesDue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=geo_DebtInstrumentRedemptionPeriodOnOrPriorToApril12018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_FivePointOneTwoFivePercentSeniorNotesDue2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt (5.875% Senior Notes) (Details) - Senior Notes - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Oct. 03, 2013	Mar. 19, 2013
5.875% Senior Notes due 2022
Debt Instrument [Line Items]
Stated interest rate	5.875%	5.875%
Debt instrument, face amount			$ 250,000,000.0
Debt instrument, coupon rate	5.875%
Debt instrument, yield to maturity	5.875%
Debt instrument, payment terms	Interest on the 5.875% Senior Notes due 2022 is payable semi-annually in cash in arrears on January 15 and July 15, commencing on January 15, 2014.
Debt instrument, frequency of payment	semi-annually
Debt instrument, commencement date of first required payment	Jan. 15, 2014
Debt instrument, maturity date	Jan. 15, 2022
Percentage of principal amount redeemable	101.00%
5.875% Senior Notes due 2022 \| Minimum \| Redemption, Period on or Prior To April 1, 2018
Debt Instrument [Line Items]
Notice period prior to redemption	30 days
5.875% Senior Notes due 2022 \| Maximum \| Redemption, Period on or Prior To April 1, 2018
Debt Instrument [Line Items]
Notice period prior to redemption	60 days
5.125% Senior Notes due 2023
Debt Instrument [Line Items]
Stated interest rate	5.125%	5.125%		5.125%
Debt instrument, face amount				$ 300,000,000.0
Debt instrument, coupon rate	5.125%
Debt instrument, yield to maturity	5.125%
Debt instrument, payment terms	Interest is payable semi-annually on April 1 and October 1 each year, beginning October 1, 2013.
Debt instrument, frequency of payment	semi-annually
Debt instrument, commencement date of first required payment	Oct. 01, 2013
Debt instrument, maturity date	Apr. 01, 2023
Percentage of principal amount redeemable	101.00%
Violation or event of default, interest payment failure, term	30 days
Violation or event of default, interest payment failure, maximum excess proceeds on sale of asset	$ 25,000,000.0
Violation or event of default, interest payment failure, failure to comply with other indenture agreements, term	60 days
5.125% Senior Notes due 2023 \| Minimum \| Redemption, Period on or Prior To April 1, 2018
Debt Instrument [Line Items]
Notice period prior to redemption	30 days
5.125% Senior Notes due 2023 \| Maximum \| Redemption, Period on or Prior To April 1, 2018
Debt Instrument [Line Items]
Notice period prior to redemption	60 days